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This study aimed to compare the antimicrobial effect of Nano-Silver Irrigant, Sodium Hypochlorite and Chlorohexidine against Enterococcus Faecalis bifilm. 60 Sixty, recently extracted, sound maxillary anterior teeth with completely formed apices and straight roots were selected in this study. Canals were instrumented using the Protaper Next system (Dentsply Sirona) 1 mm shorter from the apical foramen up to size X5 ( size# 50/06). Sterility of the teeth after complete root canal cleaning and shaping were achieved by autoclaving for 15 min at 121ºC with the teeth immersed in distilled water. Enterococcus Faecalis Biofilm was prepared by mixing 5 mL of the bacterial inoculum with sterilized BHI, then inoculated in teeth samples for 60 days. Teeth were then divided after the incubation period into three groups; 20 teeth each, and were treated by delivering the each of the tested irrigating solution using sterile plastic syringes. The first group was treated with Nano-Silver 0.02mol/L (2000ppm) while the second was treated using with Sodium Hypochlorite (NaOCl) 5.25% and the third was treated usinwith Chlorohexidine (CHX) 2.0%. Serial rinses ensured 5 minutes contact period between the aseptic solution and the bacteria. Sterile paper points size 50 were introduced into the canals and maintained for 3 min for sample collection, after which the paper points were placed in test tubes containing 2ml of sterile saline and several dilutions were prepared. 100 µL of each dilution was applied to the blood agar culture plates and incubated at 37ºC for 24 hours. A classical bacterial counting technique was used for each group after the treatment application for the recovery of viable E. faecalis on agar plates The results showed that the NaOCl had the highest antibacterial activity with high statistically significant difference with the other groups followed by the chlorhexidine group which also show statistically significant difference than the other two groups, then came the nano silver irrigant group which showed the lowest antibacterial activity among all the groups with statistically significant difference with them.

Background: Wear and surface roughness are major interacting properties that affect the function and appearance of esthetic CAD/CAM monolithic restorative materials and opposing natural dentition.Aim: Our research aimed to evaluate the wear and surface roughness of different esthetic monolithic CAD/CAM blocks and natural teeth antagonists before and after the chewing simulation procedure. Three types of esthetic CAD /CAM block materials were included in this study, nanoceramic resin (Lava Ultimate), polymer infiltrated ceramic (VITA Enamic), and lithium silicate glass ceramic enriched with zirconia (VITA Suprinity).Methodology: Twelve test samples were cut off as 2 mm thickness from size '14' blocks of each material, with a saw microtome. The polishing procedure was done according to the steps determined by the manufacturers. Enamel cusps from extracted human premolar teeth were used as antagonists. A chewing simulator was used to perform the 2-body wear test. Wear was quantified by weight loss and roughness measurement.Results: Lava Ultimate exhibited the highest wear and surface roughness while its antagonist showed the least wear and roughness. There was no difference between wear weight loss in Enamic and Suprinity. Enamic had higher roughness than Suprinity. Natural tooth antagonists of Suprinity had the highest wear and surface roughness compared to that of Lava Ultimate and Enamic. Conclusion:Lava Ultimate is the least material that produced wear and roughness in the natural antagonist thus considered the friendliest material to natural teeth. However, Enamic can be recommended as CAD/CAM restorative material regarding the wear of the restoration and its enamel antagonist.

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Background:The main difficulties encountering clinicians with patients suffering from enamel defects are bonding of orthodontic brackets to these enamel defects as well as sensitivity due to sound dentin exposure. Aim:This study aimed at evaluating the effect of Potassium Iodide (KI) application on the bond strength of orthodontic brackets bonded to Silver Diamine Fluoride (SDF) pretreated sound dentin.Methodology: Upper premolar teeth (n = 36) were collected and were randomly divided into three groups (n = 12). Group I (control) untreated sound dentin, Group II exposed dentin pretreated with SDF and Group III exposed dentin pretreated with SDF/KI. An adhesive (Assure plus) was then applied strictly according to the manufacturing's instructions. Then, each orthodontic bracket was bonded to the sound dentin surface using a direct resin composite. Fatigue bond strength test was performed via the step-test method. After debonding procedure of the brackets from the tooth surface, adhesive remnant index (ARI) scores on dentin were evaluated.Results: There was statistically insignificant differences in fatigue bond strength test results among the three tested groups as P > 0.05. Conclusion:Pretreatment of sound dentin with SDF or SDF/KI has no adverse effect on the bond strength between orthodontic brackets and sound dentin.

Background: Dental caries is a chronic, multifactorial disease, with limited background data available for the Egyptian and Kuwaiti populations. Aim of this study was to compare the prevalence of dental caries among Egyptian and Kuwaiti children in correlation with snacking habits and oral hygiene measure. Subjects and Methods:A total number of 360 Egyptian and kuwaiti children, each group comprised of 180 children (aged between 3-12 years)were examined over the period from 3 rd August 2019 till 6 th of October 2019.Demographic data, snacking habits and frequency of tooth brushing for children were recorded in a questionnaire. Dental status was analyzed using decayed, missing and filled index (dmf) for deciduous dentition and (DMF) index for permanent dentition. For mixed dentition (def ) index d(decayed),e (decayed tooth indicated for extraction) and f (filled tooth).Results: Kuwaiti children who had unhealthy ,mixed snacks (healthy/Unhealthy), twice daily, at different time of the day (BL/LD) and brushing their teeth twice daily had a significantly higher value of DMF than the Egyptian children. Also, The Kuwaiti children had a significantly higher dmf score than the Egyptian children regarding healthy snacks, mixed snacks, twice daily, at different time of the day (BL/LD) and brushing their teeth twice daily. Finally, the Kuwaiti children showed higher statistically significant difference score of def regarding Unhealthy and twice daily snacks than the Egyptian children . Conclusion:Our findings suggest that Kuwaiti children have higher caries prevalence than Egyptian children.

Background:The resistance of CAD/CAM monolithic esthetic materials to staining by commonly consumed beverages is of prime importance for the success and longevity of such restorations. Aim:The aim of the current study was to evaluate the color change of three commercially available esthetic monolithic block materials: Vita Suprinity (zirconia enriched lithium silicate glass ceramic), Lava Ultimate (Nanoceramic resin composite) and Vita Enamic (hybrid ceramic/ PICN) after immersion in commonly consumed beverages namely: coffee and cola compared to distilled water as control.Methodology: A total of 45 specimens were cut from CAD/CAM blocks where each slice was 2 mm thick. Three subgroups of each material group (n= 5) were tested according to the immersion solutions. Specimens were stored in 20 ml of each solution for 2 weeks at 37 ℃ before being tested. A spectrophotometer was employed to detect color change (ΔE) before and after immersion.Results: Coffee produced the highest color change (ΔE) in Vita Enamic while cola had the same influence on Lava Ultimate. Vita Suprinity showed the least color change compared to the other two materials on immersion in both beverages. Distilled water resulted in the highest ΔE value in Lava Ultimate. Vita Enamic and Vita Suprinity were significantly affected by immersion in coffee and cola, where immersion of Vita Enamic in coffee revealed higher ΔE compared to cola while the opposite is exhibited by Vita Suprinity showing higher ΔE in cola. Vita Suprinity showed highest color change upon immersion in distilled water with all (ΔE) values within acceptable range for color change Conclusion:Coffee can be considered a potential staining beverage. Also, cola can adversely affect color in resin-containing materials but less than coffee. Vita Suprinity can be considered the most color stable of the tested blocks. Vita Enamic may constitute a compromise regarding its color stability while Lava Ultimate exhibited inferior color stability on immersion in coffee, cola and distilled water.